Biophysical Techniques for the Evaluation of Skin Protective Creams

Barrier creams – skin protectants: can you protect skin?

“…In vivo and in vitro methods have been developed to evaluate the efficacy of BC. Frosch, Lachapelle, Wigger‐Alberti, and Zhai have extensively reviewed their efficacy 1–3,5–7 . Silicone‐based creams have not been demonstrated as being superior to their vehicle 2 .…”

“…BC are designed to prevent or reduce the penetration and absorption of irritants (and allergens) into the skin, preventing skin lesions and/or other toxic effects from dermal exposure 1–3,16,17 . BC are also called ‘skin protective creams’ (SPCs) or ‘protective creams’ (PCs), as well as ‘protective ointments’, ‘invisible glove’, ‘barrier’, ‘protective’ or ‘prework’ creams and/or gels (lotions), ‘antisolvent’ gels, and so on 1,9,18–20 . Frosch et al 1 .…”

“…BC are also called ‘skin protective creams’ (SPCs) or ‘protective creams’ (PCs), as well as ‘protective ointments’, ‘invisible glove’, ‘barrier’, ‘protective’ or ‘prework’ creams and/or gels (lotions), ‘antisolvent’ gels, and so on 1,9,18–20 . Frosch et al 1 . consider ‘skin protective creams’ a more appropriate terminology since most creams do not provide a real barrier, at least not comparable to stratum corneum.…”

“…There is minimal information on the mechanisms of BC's action. The frequently‐quoted general rule is that water in oil (W/O) emulsions are effective against aqueous solutions of irritants and oil in water (O/W) emulsions are effective against lipophilic materials 1,2,25,26 (with exceptions) 11,30 . BC may contain active ingredients presumed to work by trapping or transforming allergens or irritants 2,30 .…”

“…Their efficacy has been widely investigated by in vitro and in vivo studies; 1–7 however, their actual benefit remains sub judice in clinical trials, 1,2,4,8–14 and inappropriate BC application may exacerbate rather than ameliorate 1,2,8–12,15,16 . The role of skin protectants in cosmetic formulations is less studied.…”